MOSCOW, March 8. /TASS/. Swiss TAG Heuer decided not to extend its sponsor agreement with Russia's tennis player Mariya Sharapova, who had confirmed use of banned doping, the company told TASS on Tuesday.

The contract with the tennis player was in force to December 31, 2015, and the company was negotiating the contract extension. But on Tuesday, following the information on the doping abuse, the company decided to suspend the talks and not to extend the contract, TAG Heuer said.

Germany's Porsche for the time of doping investigation cancelled all events involving Russian tennis player Maria Sharapova, who had confirmed use of a banned doping.

The company said they were disappointed by the news Maria had announced.

Before that, also on Tuesday, the U.S. sportswear producer Nike announced termination of its cooperation with Sharapova due to the doping scandal.

On Monday, Maria told a news conference in Los Angeles that the Meldonium drug, banned by the World Anti-Doping Agency (WADA) since January 1, 2016, had been found in her doping test.

Sharapova said the International Tennis Federation had informed her in a letter in early March that she had failed her drug test.

She said WADA had notified her of the planned changes, but she had not noticed that meldonium was allowed no longer.

"I failed the test and take full responsibility for that. I received an email [December 22, 2015] from WADA about the changes happening to the banned list, and you can see prohibited items, and I didn't click on that link," Sharapova said.

Meldonium is a drug for heart problems and blood flow that got prohibited by WADA at the beginning of 2016. For its use the tennis player could be suspended for up to four years.

"I have been given a medicine called mildronate by my family doctor. A few days ago, after I received the letter, I found out that it also has another name of meldonium, which I did not know. It's very important for you to understand that for 10 years, this medicine was not on WADA's banned list, and I had been legally taking the medicine," Sharapova told journalists.

"I was getting sick very often, and I had a deficiency in magnesium and a family history of diabetes, and there were signs of diabetes. That is one of the medications, along with others, that I received," she said.

"I know many of you thought I was retiring," the tennis star said. "But if I was ever going to announce my retirement, it would probably not be in a downtown Los Angeles hotel with this fairly ugly carpet."

Six months ago, WADA warned meldonium would be banned due to "evidence of its use by athletes with the intention of enhancing performance."